Steering Angle Sensor

I have a 2006 Audi A8L 4.2, I discovered that my steering rack was leaking fluid about a week ago. Ordered a used rack from Wolf Auto. It arrived and my mechanic installed it on Thursday. Yesterday, they sent the car in for a four wheel alignment... and apparently they got that done... but it take quite a long time? But when I got the car back, the ESP was not working very well, as it engaging even while I drove the car straight ahead and very slowly? The ESP light flashed on and off applying brakes and reducing power from various wheels as if I was in a corner and sliding. Until eventually the ESP would fault out (only takes about 100-200 feet of driving straight ahead at 5kph) the center info panel on the cluster displayed "ESP Fault Found" and ESP disengaged completely (ESP light stayed on solid)... then the car drove normally.

This morning, I went over to the mechanics shop, spoke to the owner. I showed him the VCDS output and he thinks that it might be something that was not reconnected in the ABS system? He is not sure, but is going to have his top tech take a look on Monday.

I did my own google searching, specifically around the 18061 DTS code, and it appears that this code can pop up when the vehicles battery is disconnected or run down low. I know for sure that this happened, as I had alot of "low voltage" type codes when I first checked in VCDS... after a quick battery charge, and an All DTC Clear, all of those type of codes did not come back... But the Steering Angle Sensor fault in Module 03 ABS Brakes, always does come back. I have also, read that it might take a few code resets to get his one to clear? I have cleared the Module 03 fault about 3-4 times, and it always comes back... and the car drives the same as I described in the 1st paragraph.

It appears that the Steering Angle Sensor might be ok.... see VCDS Log output... the top line in the summary below for Module 00. Here is a clip of the important bits from the log file.


The symptoms from driving the car this morning are as follows: starts up nicely, no fault lights on the dash, however, when I pull away from a parked position, the ESP indicator light flashes on and off and the ESP system is engaging by applying brakes and removing power from various wheels as if I'm in a corner and sliding... but I am driving straight ahead going very slowly. It will do this for about 100-200 feet then the ESP will fault out (displaying ESP Fault Found on the center display), the ESP warning light will stay on... and the car will drive normally (pretty well the same as last night).

Any thoughts on what this could be? I'm wondering if the Steering Angle Sensor needs to be reset or aligned... I noticed in Module 03, under "Basic Settings" that there is a Steering Angle Sensor alignment entry... but since I didn't know exactly what it did, I didn't want to experiment with it.

have you any wheel bearing issues? or abs sensors.. best thing to do is go live date for the 4 wheel speed sensors and graph it, look for one or more that doesnt look right..

That sounded like a great idea.... but I have never done that before, so it required a little bit of digging on how to get in there? I went into ODB II Functions, as it mentioned it can do Live Data. From there I was doing a bit of experimenting... tried Mode 1 - Read Data... it provided a pull down of elements that I guess it can display... I selected "Vehicle Speed". I was expecting it to show 4 values, one for each speed sensor? But there were only 2 being displayed. The values as I drove seemed to be as expected.... one higher then the other when going around corners, and the same speed with going straight ahead.

You have to check first, is steering angle sensor working and does it shows approx 0 degree angle when Your steering wheel are positioned straight ahead.
You have to go to address 03 ABS and look at MVB 005/1.

MartinsX said:

You have to check first, is steering angle sensor working and does it shows approx 0 degree angle when Your steering wheel are positioned straight ahead.
You have to go to address 03 ABS and look at MVB 005/1.

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This is good info... I just hooked up the VCDS to the car and went into Module 03 ABS Brakes, then into Measuring Blocks, went to Group 005 and the first box was saying "Steering Angle Sensor (G85)"... and with the steering wheel straight ahead it was reading 360.0 degrees! If it is supposed to be reading 0.0 degrees, then maybe something is installed backwards? Seems rather unusual... but that would definitely explain the ESP having difficulty!

It also shows the 4 wheel speed sensors on Group 001.... and they all seem to working as expected, front/rear, left/right.

Just as I suspected, I was advised to give the Steering Angle Alignment a try, from Basic Settings... reset the straight ahead angle back to 0.0 degrees... saved that value... and all of the associated DTC codes cleared themselves! Test drive proved that did the trick... ESP all good now. Thanks for everyone that has helped out, much appreciated.

Make sure mechanic did not rotate steering wheel by 360 degrees during rack replacement. Or removed old rack in position "wheels straight ahead" but installed replacement with wheels turned to right or left. How You can get 360 degrees of??? OK, You relearned/recalibrated G85 and ESP system is happy now. But there is risk of damaging "clock spring" coil for airbag and MFSW buttons, if you have MFSW installed. I would remove steering wheel, remove clockspring coil, rotate it very carefully from one end to another by hand and count revolutions, then divide it by 2 and rotate it to center position and then install it back when wheels positioned "straight ahead". Then relearn G85.

MartinsX said:

Make sure mechanic did not rotate steering wheel by 360 degrees during rack replacement. Or removed old rack in position "wheels straight ahead" but installed replacement with wheels turned to right or left. How You can get 360 degrees of??? OK, You relearned/recalibrated G85 and ESP system is happy now. But there is risk of damaging "clock spring" coil for airbag and MFSW buttons, if you have MFSW installed. I would remove steering wheel, remove clockspring coil, rotate it very carefully from one end to another by hand and count revolutions, then divide it by 2 and rotate it to center position and then install it back when wheels positioned "straight ahead". Then relearn G85.

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I will most certainly speak to the mechanic on Monday and ask him about all of the things you mentioned. I was present for most of the installation procedure, and I know that he did not seem to ever have the steering wheel turned... but most certainly I was not there for the whole day. So those are all good things to inquire about. Also, I was not present for the 4-wheel alignment (done at another shop), but as it has been explained to me, I don't think they would ever need to remove the steering wheel to perform that task... but certainly worth asking.

While I was researching this issue, I have read other people that have had their battery go dead or low-enough, that the steering angle sensor can go off and they had to re-calibrate it as well. Unfortunately, they did not list out exactly the degrees of angle that it went off by, in most cases they took it to a dealer and they performed a re-calibration.

If i get a 00778 code and the steering angle reads only 0° can the G85 be faulty?

raziel90 said:

If i get a 00778 code and the steering angle reads only 0° can the G85 be faulty?

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Story of my life.
If sensor g85 was faulty it would say "Defective"
Did you try to start the car, turn the Steering wheel left one turn and right one turn and then perform the drive up to 20km/pH and then come to a stop?